| 1. |
- Langer, Sarka, 1960, et al.
(författare)
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Impacts of fuel quality on indoor environment onboard a ship: From policy to practice
- 2020
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Ingår i: Transportation Research Part D-Transport and Environment. - : Elsevier BV. - 1361-9209 .- 1879-2340. ; 83
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Tidskriftsartikel (refereegranskat)abstract
- Environmental considerations, concerning the negative impacts of ship exhaust gases and particles on ambient air quality, are behind the requirements of cleaner marine fuels currently applied in designated emission control areas (ECAs). We investigated the impact of a ship operating on two types of fuel on the indoor air quality onboard. Gaseous and particulate air pollutants were measured in the engine room and the accommodation sections on-board an icebreaker operating first on Heavy Fuel Oil (HFO, 1%-S), and later Marine Diesel Oil (MDO, 0.1%-S). Statistically significant decrease of SO2, NOx, PM2.5 and particle number concentration were observed when the ship was operating on MDO. Due to the higher content of alkylated PAHs in MDO compared to HFO, the concentration of PAHs increased during operation on MDO. The particulate PAHs classified as carcinogens, were similar to or lower in the MDO campaign. Chemical analysis of PM2.5 revealed that the particles consisted mainly of organic carbon and sulfate, although the fraction of metals was quite large in particles from the engine room. Principal Component Analysis of all measured parameters showed a clear difference between HFO and MDO fuel on the indoor environmental quality on-board the ship. This empirical study poses a first example on how environmental policy-making impacts not only the primary target at a global level, but also brings unexpected localized benefits at workplace level. The study emphasizes the need of further investigations on the impact of new marine fuels and technologies on the indoor air environments on board.
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| 2. |
- Angot, H., et al.
(författare)
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Chemical cycling and deposition of atmospheric mercury in polar regions: review of recent measurements and comparison with models
- 2016
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 16:16, s. 10735-10763
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Tidskriftsartikel (refereegranskat)abstract
- Mercury (Hg) is a worldwide contaminant that can cause adverse health effects to wildlife and humans. While atmospheric modeling traces the link from emissions to deposition of Hg onto environmental surfaces, large uncertainties arise from our incomplete understanding of atmospheric processes (oxidation pathways, deposition, and re-emission). Atmospheric Hg reactivity is exacerbated in high latitudes and there is still much to be learned from polar regions in terms of atmospheric processes. This paper provides a synthesis of the atmospheric Hg monitoring data available in recent years (2011-2015) in the Arctic and in Antarctica along with a comparison of these observations with numerical simulations using four cutting-edge global models. The cycle of atmospheric Hg in the Arctic and in Antarctica presents both similarities and differences. Coastal sites in the two regions are both influenced by springtime atmospheric Hg depletion events and by summertime snowpack re-emission and oceanic evasion of Hg. The cycle of atmospheric Hg differs between the two regions primarily because of their different geography. While Arctic sites are significantly influenced by northern hemispheric Hg emissions especially in winter, coastal Antarctic sites are significantly influenced by the reactivity observed on the East Antarctic ice sheet due to katabatic winds. Based on the comparison of multi-model simulations with observations, this paper discusses whether the processes that affect atmospheric Hg seasonality and inter-annual variability are appropriately represented in the models and identifies research gaps in our understanding of the atmospheric Hg cycling in high latitudes.
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| 3. |
- Beko, G., et al.
(författare)
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The Indoor Chemical Human Emissions and Reactivity (ICHEAR) project: Overview of experimental methodology and preliminary results
- 2020
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Ingår i: Indoor Air. - : Hindawi Limited. - 1600-0668 .- 0905-6947. ; 30:6, s. 1213-1228
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Tidskriftsartikel (refereegranskat)abstract
- With the gradual reduction of emissions from building products, emissions from human occupants become more dominant indoors. The impact of human emissions on indoor air quality is inadequately understood. The aim of the Indoor Chemical Human Emissions and Reactivity (ICHEAR) project was to examine the impact on indoor air chemistry of whole-body, exhaled, and dermally emitted human bioeffluents under different conditions comprising human factors (t-shirts/shorts vs long-sleeve shirts/pants; age: teenagers, young adults, and seniors) and a variety of environmental factors (moderate vs high air temperature; low vs high relative humidity; presence vs absence of ozone). A series of human subject experiments were performed in a well-controlled stainless steel climate chamber. State-of-the-art measurement technologies were used to quantify the volatile organic compounds emitted by humans and their total OH reactivity; ammonia, nanoparticle, fluorescent biological aerosol particle (FBAP), and microbial emissions; and skin surface chemistry. This paper presents the design of the project, its methodologies, and preliminary results, comparing identical measurements performed with five groups, each composed of 4 volunteers (2 males and 2 females). The volunteers wore identical laundered new clothes and were asked to use the same set of fragrance-free personal care products. They occupied the ozone-free (<2 ppb) chamber for 3 hours (morning) and then left for a 10-min lunch break. Ozone (target concentration in occupied chamber ~35 ppb) was introduced 10 minutes after the volunteers returned to the chamber, and the measurements continued for another 2.5 hours. Under a given ozone condition, relatively small differences were observed in the steady-state concentrations of geranyl acetone, 6MHO, and 4OPA between the five groups. Larger variability was observed for acetone and isoprene. The absence or presence of ozone significantly influenced the steady-state concentrations of acetone, geranyl acetone, 6MHO, and 4OPA. Results of replicate experiments demonstrate the robustness of the experiments. Higher repeatability was achieved for dermally emitted compounds and their reaction products than for constituents of exhaled breath.
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| 4. |
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| 5. |
- Cabovska, Blanka, 1990, et al.
(författare)
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A study on the relationship between energy performance and IEQ parameters in school buildings
- 2021
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Ingår i: E3S Web of Conferences. - : EDP Sciences. - 2555-0403 .- 2267-1242. ; 246
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Konferensbidrag (refereegranskat)abstract
- Over the last decades, strong focus has been placed on the energy efficiency of buildings; not least school buildings. Energy performance (EP) of buildings is nowadays in principle described by one single indicator based on purchased energy in kWh/year.m2. Another important building performance aspect is the indoor environmental quality. This study's overarching goal is to identify school buildings with a good balance between energy performance and indoor environment. Thus, this paper investigates possible correlations between information given in energy performance certificates (EPCs/e.g. energy use, year of construction, type of ventilation) and measured indoor environmental parameters. The work comprises investigation of approximately 20 school buildings with different ventilation systems in Gothenburg. In-situ investigations of the buildings' properties and ventilation systems were conducted. Indoor environmental parameters were recorded during one week in each classroom. In this paper, indoor temperature, absolute humidity added indoors and CO2 concentration data are compared with the corresponding school's energy performance data and ventilation type. Results suggest that mechanically ventilated buildings have clearer relationships between energy performance, building indicators and measured indoor environment. For buildings such as naturally ventilated, the relationships are usually weak, and the values spread over much wider ranges.
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| 6. |
- Cabovska, Blanka, 1990, et al.
(författare)
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Measured and perceived IEQ under different ventilation strategies in Swedish classrooms
- 2022
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Ingår i: 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022.
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Konferensbidrag (refereegranskat)abstract
- Indoor environmental quality was assessed in Swedish primary school classrooms grouped into three categories based on the ventilation system: 1) natural or exhaust ventilation, 2) balanced mechanical ventilation systems with constant air volume (CAV), 3) balanced mechanical ventilation systems with variable air volume (VAV). Measurements of NO2, ozone, TVOC, formaldehyde, PM10, and PM2.5 and a questionnaire survey were conducted. The concentrations of pollutants were integrated into Indoor Air Pollution Index allowing the rank comparison of classrooms. Children’s perception scores were calculated based on the questionnaire responses. Naturally ventilated classrooms had higher level of air pollution. No significant differences in pollutant levels were observed between classrooms with CAV and VAV systems. The type of ventilation system affected the subjective assessment of indoor air quality; it was worst in naturally ventilated classrooms.
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| 7. |
- Dalenbäck, Jan-Olof, 1954, et al.
(författare)
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Låg luftfuktighet i svenska bostäder – ett problem?
- 2021
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Ingår i: Energi & miljö. ; 10
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Låg relativ luftfuktighet inomhus är ett problem i många svenska bostäder under uppvärmningssäsongen, mera i lägenheter än i småhus, i hus byggda efter 1985 och i de norra delarna av landet. Ventilation av nya bostäder blir en allt viktigare faktor med avseende på luftfuktigheten inomhus.
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| 8. |
- Domhagen, Fredrik, 1987, et al.
(författare)
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Modelling VOC levels in a new office building using passive sampling, humidity, temperature, and ventilation measurements
- 2023
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Ingår i: Building and Environment. - 0360-1323. ; 238
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Tidskriftsartikel (refereegranskat)abstract
- New buildings often have high initial concentrations of VOCs that, although not necessarily harmful, may be disturbing and cause discomfort among occupants. In new buildings, running the ventilation system continuously and at full rate during the first year is common practice to reduce VOC levels. However, the drawback of such an arbitrary strategy is the risk of over-ventilating with unnecessary heat losses as a consequence. In this article, a new approach, a VOC-passport, is developed where early measurements of VOCs together with a calculation model are used to find an optimized ventilation strategy. The proposed calculation model is tested on two newly built office rooms where VOCs were measured using passive samplers, together with temperature, humidity and ventilation rates, and it shows good agreement with measurements. An example of how a daily ventilation schedule may look like if optimized with the prosed model is presented. The example illustrates that in buildings where VOC levels are allowed to increase periodically, VOC levels can be kept at acceptable levels during occupancy hours if the effective storage capacity is known. The proposed method has a potential to improve the indoor air quality in new buildings without compromising energy efficiency.
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| 9. |
- Domhagen, Fredrik, 1987, et al.
(författare)
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Theoretical Threshold for Estimating the Impact of Ventilation on Materials’ Emissions
- 2024
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Ingår i: Journal of Environmental Science and Technology. - 0013-936X .- 1520-5851. ; 58:11, s. 5058-5067
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Tidskriftsartikel (refereegranskat)abstract
- In new buildings, nonoccupant VOC emissions are initially high but typically decrease within months. Increased ventilation is commonly used to improve indoor air quality, assuming it speeds up VOC off-gassing from materials. However, previous research presents inconsistent results. This review introduces a simplified analytical model to understand the ventilation-emission relationship. By combining factors such as diffusivity, emitting area, and time, the model suggests the existence of a theoretical ventilation threshold beyond which enhanced ventilation has no further influence on emission rates. A threshold of approximately 0.13 L s-1 m-2 emitting area has been found for various VOCs documented in the existing literature, with which the conflicting results are explained. It is also shown that the threshold remains notably consistent across different boundary conditions and model resolutions, indicating its suitability for real-world applications.
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| 10. |
- Fischer, Andreas, et al.
(författare)
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Chemistry and indoor air quality in a multi-storey wooden passive (low energy) building : Formation of peroxyacetyl nitrate
- 2014
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Ingår i: Indoor + Built Environment. - : SAGE Publications Ltd. - 1420-326X .- 1423-0070. ; 23:3, s. 485-496
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Tidskriftsartikel (refereegranskat)abstract
- Indoor air measurements were conducted in one unoccupied apartment of a 'near-zero-energy' residential building with a unique, wooden construction. Ozone, NO2, fine particles and volatile organic compounds, formaldehyde, acetaldehyde and peroxyacetyl nitrate (PAN) were measured under 'as is' conditions and after intentional intervention by adding ozone to simulate an ambient air ozone episode. Undisturbed concentrations were: O 3 5-10 ppb, NO2 5-8 ppb, fine particles 2000-5000 cm -3, formaldehyde 35 ± 5 μg/m3, PAN 0.3 ppb. During intervention, O3 was 50-60 ppb, NO2 15-20 ppb, fine particles 20,000-25,000 cm-3, formaldehyde 44 ± 2 μg/m3 and PAN 0.7-1 ppb. It was shown that chemical reactions had taken place in the indoor air. Ozone-initiated chemistry produced various aldehydes, PAN and, as a direct response to increased ozone concentrations, also fine particles. Calculations made by a simple model of PAN formation showed that an air change rate of around 0.2 h-1 would provide optimum conditions for PAN formation in a setting comparable to that of the investigated apartment. This air change rate is well below the Swedish national minimum of 0.5 h-1. Further, the calculations show that the non-photochemical PAN formation could be a consequence of mixing ozone and nitrogen dioxide with terpenes and acetaldehyde.
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